Yamazoe Hironori, Iwata Hiroo
Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Biomaterials. 2006 Oct;27(28):4871-80. doi: 10.1016/j.biomaterials.2006.05.006. Epub 2006 Jun 12.
Transplantation of dopamine neurons is a promising approach to treat Parkinson's disease. Embryonic stem (ES) cells are expected to be a cell source of the dopaminergic neurons. Various difficulties, however, need to be overcome to realize cell therapy of Parkinson's disease using dopaminergic neurons from ES cells. For example, they are highly sensitive to enzymatic treatment and physical dissociation, and the patient's immune system may attack the transplanted cells. In this study, we attempted to induce dopaminergic neurons from mouse ES cells enclosed in hollow fibers using conditioning medium from PA6 cells, the stromal cells derived from skull bone marrow. beta-tubulin type III positive cells and tyrosine hydroxylase positive cells were efficiently derived in hollow fibers after 16 days in culture, and dopamine release was observed when the hollow fibers containing cells were exposed to 56mm KCl for 15min to induce dopamine release through depolarization of the neurons. By our procedure, enclosure of dopaminergic neurons in hollow fibers was easily performed without loss of cells, and the hollow fiber membrane is expected to efficiently protect dopaminergic neurons from mechanical disturbances and attacks by the host immune system. Although there are many issues, especially related to immuno-isolation, that still remain to be addressed, we believe that differentiation of ES cells within hollow fibers is one of the crucial procedures so that cell therapy of Parkinson's disease can be realized.
多巴胺神经元移植是治疗帕金森病的一种有前景的方法。胚胎干细胞有望成为多巴胺能神经元的细胞来源。然而，要利用胚胎干细胞来源的多巴胺能神经元实现帕金森病的细胞治疗，还需要克服各种困难。例如，它们对酶处理和物理解离高度敏感，而且患者的免疫系统可能会攻击移植的细胞。在本研究中，我们尝试使用源自颅骨骨髓的基质细胞PA6细胞的条件培养基，从小鼠胚胎干细胞在中空纤维中诱导多巴胺能神经元。培养16天后，在中空纤维中高效地产生了β-微管蛋白III阳性细胞和酪氨酸羟化酶阳性细胞，当含有细胞的中空纤维暴露于56mM KCl 15分钟以通过神经元去极化诱导多巴胺释放时，观察到了多巴胺的释放。通过我们的方法，将多巴胺能神经元包裹在中空纤维中很容易进行，且不会损失细胞，并且中空纤维膜有望有效地保护多巴胺能神经元免受机械干扰和宿主免疫系统的攻击。尽管仍有许多问题，特别是与免疫隔离相关的问题有待解决，但我们认为在中空纤维内分化胚胎干细胞是实现帕金森病细胞治疗的关键步骤之一。
